Carbureter



dit

THUMAS W. BURR, F STNEHAM, MASSAHTIFETTS.

GARBURETER.

assenso,

.application ler November 28, 1917.

To all fwiom it may concern:

Be it known that l, THOMAS WV. BURR, a citizen of the United States, anda resident of Stoneham, county of Middlesex, and State of Massachusetts,have invented an improvement in Carbureters, of Which the following is aspecification.

This invention relates to certain improvements in carbureters `of thetype in which the lliquid fuel is `drawn up thereto from a low leveltank', which is open to atmospheric pressure, by the suction action ofthe engine; and more particularly to certain. improve-J ments in a fuelfeeding device of the type disclosed in my pending application, SerialNo. 196,943, in which no auxiliary reservoir is employed, the supplypipe leading directly from the main tank to the carbureting chamber, sothat it is practically dry at all times in that it, at no time, containsany sub-- stantial quantity of fuel in liquid form.

ln this device also, the liquid fue] supply pipe, which entends from thelowdevel tank, opens to the carbureting chamber at the ene gine side ofthe throttle, which. controls the air supply thereto, so that said pipeis open to the full suction action of the engine, and the dischargetherefrom is controlled by a needle valve which is automatically.operated With the throttle in'predetermined proportion, so that therelative proportions of air and fuel are essentially maintained anderall conditions.,

The object of the present invention is prii marily to provide asimplified form of device having` the above characteristics, so 'thatthe cost of manufacture thereof may be reduced, as compared with priordevices for the purpose; and the danger of its getting out of order willbe reduced to a minimum, and to accomplish this object Withoutimpairment of eiiiciency, but with possible increase in efficiency.

I accomplish this object by means herein after described and illustratedin the accompanying' drawing. in which:

Figure l is a side elevation of fuel feeding device embodying myinvention.

Fig. 2 is a plan vien7 thereof.

Fig. 3 is a sectional view on the line 3W?.

specification of Letters EPatent.

Patented lien.. ad., this.. Serial No. Rodda-.

Fig. d is a sectional View on the line fit-t Fig. l. Fig. 5 is a generalview, illustrating the combinationn As shown in the drawing, the liquidvaporG lenig device, embodying the present invention, comprises a casingo oi cylindrical' form, having ears a at one end, adapted to connect thesame directly to the intake manifold of the engine, and having itsopposite end closed by a cap removably secured thereto. An air supplypipe c, of substantially smaller internal cross-sectional area than thatof said casing, and which, in practice, is arranged so that the airpassing therethrough will be heated, is connected to said casing atright angles; and a hollow cylindrical throttle valve al, closed at oneend and open at the opposite end, and having` a port al in one sidethereof, is disposed in said raising' with its closed end adjacent saidcap 7), and so arranged that, when rotated, its port .may be broughtinto register withthe opening in the casing1 to Which. the air supplypipe c is connected. The head end of said. valve d is provided with atubular stem e which extends through said cap if and is rotatabletherein, and a nut j, having an operating; arm f extending therefrom, ismounted on the outer end of said stem and is locked in position thereonby a set screw g, or other suitable means, to provide means forcontrolling; said valve, the movements of which are limited. by fingers.e on said. arm, arranged to engage a stop lug e' on the cap l).

rllhe liquid fuel supply pipe j' is extendedV from the bottom of asuitably vented, low level, liquid' fue] supply tank it into saidcasing, at a point between the open end of the throttle valve and theend of the casing which is connected directly to the intalte manifold;the inner end of said pipe beingF extended beyond the longitudinalcenter of said casing, and having a nipple m mounted therein, the centerline of its bore being coincident with the center line of the casing,liavinpr a side opening' connecting said bore with said supply pipe j.rlhe bore of said nipple, next the suction end of the casing, ispreferably enlarged and Covered with a 'iti fine mesh screen m', asshown in Fig. 4,1and a shoulder m2 is formed in said bore between saidenlargement and the point of connection of said supply pipe therewith. Atapering valve seat is formed in said shoulder; against which a needlevalve a is adapted to seat, the stem of which is extended through andthreaded in the stem?l of the throttle valve and through the bore ofsaid nipple. 'Ifheouter end of the needle valve stern` is provided witha head 0, by means of which it may be conveniently adjusted, and a locknut p is providedion said stem for locking the same in adjustedposition. An inclined is formed on the' outer end of the headconcentrically with cam-faced proJection b the needle valve stem, and acorrespondingly inclined cam face is formed on the nut said 'faces beingconstantly held in Contact by a spring 'g surrounding the stem t andinterposed between `the inner side of the cap b and the head end of` thevalve In practice the vparts are so adJusted that lwhen they are ininitial position, and one port and become mixed therewith. Under theseconditions only suiiicient mixture will be supplied to run the engine'without load. It will be understood that the exact initial adjustmentsof the valves will dependto a large extent on conditions, and that therelative extent of opening of the two valves, when in initial position,will be varied according to particular requirements.

A In the initial position of the throttle valve, its closed end is heldat a suiiicient distance from the cap to permit the same to be axiallymoved toward said cap tor a distance equal to that which it is necessaryto move the needle-valve axially, to. move the same from a position, inwhich it is seated, to its fully open position, so that when the arm fis movedto -pen the throttle valve, as its cam nut-f1 rides up on thecam projection b', the throttle valve will be moved axially toward saidcap as itis rotated, and as the needle valve n is mounted iu the stem otthe throttle valve. it will be carried away from its seat by thethrottle valve, as thelatter is opened; the relative arrangements ofcams and valve ports being such that the volume of air, whichfmay beydrawn 'in through the port fl of; the throttle. and the volume of liquidwhichwill be permitted to escape past the needle valve, will be indirect and Vconstant proportion ind all positions thereof. Then thevalves are closed, the `opposite movements will take place, as will beobvious.

Itis essential to the successful operation of the above described devicethat the cross sectional area of the air inlet be lessthan'- that of theair suction chamber to which vthe engine is connected, so that theengine may act to A'reduce the air pressure in said chamber to asuiiicient extent in the completely open position of the throttle valve,to insure the discharge of liquid fuel into the mixing chamber insufficient quantities to maintain the desiredl vproportions of air andfuel.

The device above described is not only of simple construction, but itisunlikely to et out of order, and it is adapted to be ad- Justed tomeet widely diHering demands.

' I claim 1. A carbureter comprising a' casing having acarburetingchamberto which air and fuel are supplied, a cylindrical throttle valvemounted for axial movement in said casing and rotatable to vary the airsupply to said chamber, a needle valve carried by said throttle valve inaxial alinement therewith and arranged to be operated to vary the fuelsupply to said chamber when moved axially, and means to causesimultaneous axial and rotational movements of said throttle valve, tooperate saidneedle valve, and to cause simultaneous and correspondingcontrol of the air and fuel supply to said chalnber.

Q. A carbureter comprising a casing having a. carbureting chamber towhich air and fuel are supplied, a cylindrical throttle valve mountedfor axial movement in said casing and rotatable to vary the air supplyto said chamber, a needle valve carried by said throttle valve in axialalinement therewith and arranged to be operated to vary the 't'uelsupply to said chamber when moved axially. means to cause sin'iultaneousaxial and rotational movements,'of said throttle valve to operate saidneedle valve and simultaneously and eorre'spondiugly control the air andfuel supply to said chamber and means permitting axial adjustment ofsaid needle valve. while said throttle valve, is

held against rotation, to varv the fuel supply relative to the airsupply.

3. .i\ carburoter compr1slng a casing havrotationally to vary the airsupply to said chamber, a spring arranged to move said throttle valveaxially in one direction and a, cam for 'moving it in the oppositedirection when the valve is rotated, to cause corresponding axialmovements of seidv needle valve and simultaneous and correspondingcontrol of the air and Jfuel' supply to said chamber.

In testimony whereof, I have signed my 10 name to this specification.

THOMAS W. BURR. Witness:

L. H. HARRIMAN.

